Regulating device control system, regulating device control method, and recording medium

ABSTRACT

A regulating-device-control system for controlling the operation of regulating devices for regulating the balance between electric power supply and demand includes: memory means storing, for each regulating device, correlation information expressing correlation of a state of the regulating device, an amount of power allotted to the regulating device, and an amount of variability in performance of the regulating device; determination means receiving state information that expresses the state of each regulating device and electric power information that expresses an amount of regulated power required for regulating the balance between electric power supply and demand, and, based on the correlation information, the state information, and the electric power information, determining the amount of electric power to be allotted to each regulating device such that the total value of the amount of variability in performance of each of the regulating devices is minimized under conditions in which the state of each regulating device is the state expressed by the state information and the total value of the amount of power to be allotted to the regulating devices is the amount of regulated power; and control means controlling the operation of each regulating device based on the determination result of the determination means.

TECHNICAL FIELD

The present invention relates to a regulating device control system, aregulating device control method, and a recording medium, and moreparticularly relates to a regulating device control system, a regulatingdevice control method, and a recording medium for controlling aplurality of regulating devices for regulating the balance betweenelectric power supply and demand in an electric power system.

BACKGROUND ART

Methods, which have been adopted for regulating the balance betweenpower supply and demand in an electric power system, include a methodfor controlling the output of thermal power generation and a method ofappropriately operating pumping-up hydraulic power generation whilecontrolling the output of thermal power generation.

As renewable power sources such as photovoltaic or wind powergeneration, in which the amount of generated power depends on weather,are incorporated as distributed power sources in electric power systemsin the future, concern arises that these distributed power sources mayadversely affect the balance between power supply and demand.

A method of regulating power supply and demand that uses thermal powergeneration and pumping-up hydraulic power generation may by itself beinadequate to compensate for imbalance in power supply and demand thatis brought about by the distributed power sources. As a result, a newmethod of regulating electric power supply and demand is now essential.

One method, which is thought to be a new method of regulating electricpower supply and demand, employs apparatuses such as “storage cells,”“electric vehicles (EV),” and heat-pump water heaters (HP) (hereinbelowreferred to as “electric power apparatuses”) that are linked to thepower distribution network of an electric power system as regulatingdevices for regulating the balance between electric power supply anddemand.

Patent Document 1 describes an electric power system control device thatregulates the balance between electric power supply and demand by usingconsumer-side secondary batteries (ES), which are electric powerapparatuses, as regulating devices for regulating the balance betweenelectric power supply and demand.

LITERATURE OF THE PRIOR ART Patent Documents

Patent Document 1: Japanese Unexamined Patent Application PublicationNo. 2006-094648

SUMMARY OF THE INVENTION Problem to be Solved by the Invention

The performance of a regulating device changes according to theconditions of use.

For example, deterioration of a regulating device progresses with use,and the performance of the regulating device worsens as thedeterioration progresses. The degree of the progression of deteriorationof a regulating device varies according to the amount of electric powerregulated by the regulating device for regulating the balance betweenelectric power supply and demand and the state of the regulating device(for example, the temperature). The change in the performance of theregulating device further depends on properties other than thedeterioration of the regulating device.

A method is therefore to be desired for distributing electric power to aplurality of regulating devices that are used for regulating the balancebetween electric power supply and demand to reduce the amount ofvariability in the performance of the plurality of regulating devices.

It is an object of the present invention to provide a regulating devicecontrol system, regulating device control method, and recording mediumthat can solve the above-described problem.

Means for Solving the Problem

The regulating device control system according to the present inventionis a regulating device control system that controls the operation of aplurality of regulating devices for regulating the balance betweenelectric power supply and demand in an electric power system, andincludes:

memory means that stores, for each of the regulating devices,correlation information that represents the correlation of the state ofthe regulating device, the amount of electric power allotted to theregulating device, and the amount of variability in the performance ofthe regulating device;

determination means that receives state information that indicates thestate of each regulating device and electric power information thatindicates the amount of regulated power necessary for the regulation ofthe balance between electric power supply and demand and, based on thecorrelation information, the state information, and the electric powerinformation, determines the amount of electric power to be allotted toeach of the regulating devices such that the total value of the amountof variability in the performance of each of the regulating devices isminimized under conditions in which the state of each of the regulatingdevices is the state indicated in the state information and the totalvalue of the amount of electric power allotted to each of the regulatingdevices is the amount of regulated power; and

control means that controls the operation of each of the regulatingdevices based on the determination results of the determination means.

The regulating device control method according to the present inventionis a regulating device control method in a regulating device controlsystem that controls the operation of a plurality of regulating devicesfor regulating the balance between electric power supply and demand inan electric power system and includes:

for each of the regulating devices, storing in memory means: correlationinformation that indicates the correlation of the state of theregulating device, the amount of electric power to be allotted to theregulating device, and the amount of variability in the performance ofthe regulating device;

receiving state information that indicates the state of each regulatingdevice and electric power information that indicates the amount ofregulated power required for the regulation of the balance between theelectric power supply and demand, and, based on the correlationinformation, the state information, and the electric power information,determining the amount of electric power to be allotted to eachregulating devices such that the total value of the amount ofvariability in performance of each of the regulating devices isminimized under conditions in which the state of each of the regulatingdevices is the state indicated in the state information and the totalvalue of the amount of electric power allotted to each of the regulatingdevices is the amount of regulated power; and

controlling the operation of each of the regulating devices based on theresults of the determination.

The recording medium according to the present invention is a recordingmedium that is readable by a computer and on which a program is recordedfor causing a computer to execute:

a storage procedure of storing in memory means, for each of a pluralityof regulating devices for regulating the balance between electric powersupply and demand in an electric power system, correlation informationthat indicates the correlation of state information of the regulatingdevice, the amount of electric power to be allotted to the regulatingdevice, and the amount of variability in performance of the regulatingdevice;

a determination procedure of receiving state information that indicatesthe state of each of the regulating devices and electric powerinformation that indicates the amount of regulated power required forregulating the balance between the electric power supply and demand,and, based on the correlation information, the state information, andthe electric power information, determining the amount of electric powerto be allotted to each of the regulating devices such that the totalvalue of the amount of variability in performance of each of theregulating devices is minimized under conditions in which the state ofeach of the regulating devices is the state indicated in the stateinformation and the total value of the amount of electric power allottedto each of the regulating devices is the amount of regulated power; and

a control procedure of controlling the operation of each of theregulating devices based on the results of the determination.

Effect of the Invention

According to the present invention, variability in the performance of aplurality of regulating devices that are used for regulating the balancebetween electric power supply and demand can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an electric power control system that adopts the regulatingdevice control system of the first exemplary embodiment of the presentinvention.

FIG. 2 shows an example of the value of D_(k) when temperature T₀ is 15,20, and 25 degrees.

FIG. 3 is a sequence diagram for describing the operation of theelectric power control system.

FIG. 4 shows cell management unit 5 that is made up of storage unit 52,determination unit 53, and control unit 54.

FIG. 5 shows an electric power control system that adopts the regulatingdevice control system of the second exemplary embodiment of the presentinvention.

FIG. 6 shows an example of the value of D_(k) when temperature SoC₀ is0.5, 0.6, and 0.7.

MODE FOR CARRYING OUT THE INVENTION

Exemplary embodiments of the present invention are next described withreference to the accompanying drawings.

First Exemplary Embodiment

FIG. 1 shows an electric power control system that adopts the regulatingdevice control system of the first exemplary embodiment of the presentinvention.

In FIG. 1, the electric power control system includes: electric powersystem 1, power line 2, storage cell systems 31-3 n (where n is aninteger equal to or greater than 2), EMU (Energy Management Unit) 4, andcell management unit 5.

Electric power system 1 is a system for supplying electric power toconsumers, and for example, includes a power plant such as a thermalpower plant, a renewable power source, and a transformer. Electric powersystem 1 supplies the generated electric power from the power plant orrenewable power source to power line 2 by way of the transformer.Typically, power line 2 is included in electric power system 1, but inFIG. 1, electric power system 1 and power line 2 are shown separately inthe interest of simplifying the explanation.

Storage cell systems 31-3 n are used for regulating the balance betweenelectric power supply and demand in electric power system 1. Forexample, storage cell systems 31-3 n are each managed by consumers. Anumber of storage cell systems 31-3 n may also be managed on theelectric power supply side.

Each of storage cell systems 31-3 n includes: communication unit 301, ES(Energy storage) 302, inverter 303, BMU (Battery Management Unit) 304,and temperature detectors 304 a and 304 b. Regarding communication unit301, ES 302, inverter 303, BMU 304, and temperature detectors 304 a and304 b, FIG. 1 shows the components in storage cell system 31.

Communication unit 301, ES 302, inverter 303, BMU 304, and temperaturedetectors 304 a and 304 b in storage cell system 31 are next described.

Communication unit 301 communicates with cell management unit 5.

ES 302 is one example of the regulating device.

ES 302 is, for example, a stationary battery or a secondary battery inan electric vehicle. ES 302 is, for example, a lithium-ion secondarybattery. ES 302 is not limited to a lithium-ion secondary battery andmay be any type of storage cell.

Inverter 303 converts alternating-current voltage from power line 2 todirect-current voltage during charging of ES 302 and thus charges ES 302by this direct-current voltage. During discharging of ES 302, inverter303 converts the direct-current voltage from ES 302 toalternating-current voltage and supplies this alternating-currentvoltage to power line 2 to thus discharge ES 302.

BMU 304 controls inverter 303 in accordance with operation instructionsfrom cell management unit 5 to control the charging and discharging ofES 302.

In addition, BMU 304 transmits to cell management unit 5 by way ofcommunication unit 301 the detection results of temperature detector 304a that detects the temperature To of ES 302 and the detection results oftemperature detector 304 b that detects the ambient temperature T_(E)(the temperature of the environment in which ES 302 is placed) of ES302.

Still further, BMU 304 calculates and manages the amount of reduction ofthe capacity D_(total,k) from the initialization of ES 302 in storagecell system 31. BMU 304 transmits the amount of reduction of capacityD_(total,k) to cell management unit 5 by way of communication unit 301.The method of calculating the amount of reduction of capacityD_(total,k) from the initialization of ES 302 is known technology, and adetailed explanation is therefore here omitted.

The temperature T₀ of ES 302, the ambient temperature T_(E) of ES 302,and the amount of reduction of capacity D_(total,k) of ES 302 areexamples of the state of ES 302.

An explanation regarding communication unit 301, ES 302, inverter 303,BMU 304, and temperature detectors 304 a and 304 b in each storage cellsystem other than storage cell system 31 (hereinbelow referred to as“storage cell system 3 a”) may be derived by merely changing the words“storage cell system 31” to “storage cell system 3 a” in the explanationregarding communication unit 301, ES 302, inverter 303, BMU 304, andtemperature detectors 304 a and 304 b in storage cell system 31described above.

EMU 4 calculates the amount of regulated power P_(t) that is requiredfor regulation of the balance between electric power supply and demand.For example, when there is a portion that exceeds the referencethreshold value that is the standard for judging the presence or absenceof a peak-cutting process (hereinbelow referred to as the “peak-cuttingobject portion”) on the future estimated total demand curve that hasbeen provided or calculated in advance, EMU 4 calculates the amount ofelectric power that corresponds to this peak-cutting object portion asthe amount of regulated power P_(t).

In the present exemplary embodiment, EMU 4 takes the value of the amountof regulated power P_(t) as a positive value when demand for electricpower is necessary for regulating the balance between electric powersupply and demand and takes the value of the amount of regulated powerP_(t) as a negative value when supply of electric power is necessary forregulating the balance between electric power supply and demand.

EMU 4 transmits power information that indicates the amount of regulatedpower P_(t) to cell management unit 5.

In the present exemplary embodiment, EMU 4 calculates the amount ofregulated power P_(t) for the passage of each time interval Δt andtransmits the power information that indicates the amount of regulatedpower P_(t) to cell management unit 5.

Cell management unit 5 is one example of the regulating device controlsystem.

Cell management unit 5 controls the operation of storage cell systems31-3 n, and further, the operation of each ES 302 to regulate thebalance between electric power supply and demand in electric powersystem 1.

Cell management unit 5 includes: communication unit 51, storage unit 52,determination unit 53, and control unit 54.

Communication unit 51 communicates with each of storage cell systems31-3 n.

Communication unit 51 receives, for example, the detection results ofthe temperature T₀ of ES 302, the detection results of the ambienttemperature T_(E) of ES 302, and the result of calculation of the amountof reduction of capacity D_(total,k) of ES 302 from each of storage cellsystems 31-3 n and supplies each of the detection results andcalculation results to determination unit 53.

Storage unit 52 is one example of the memory means.

Storage unit 52 stores for each of ES 302 within storage cell systems31-3 n correlation information that indicates the correlation of thestate of ES 302, the amount of electric power allotted to ES 302, andthe amount of variability in deterioration of ES 302. The amount ofchange in deterioration of ES 302 is one example of the amount ofvariability in the performance of ES 302.

For example, storage unit 52 stores the following Formula (1) as thecorrelation information for each ES 302 within storage cell systems 31-3n.

Formula 1

amount of change in deterioration=D _(k)(P _(k) , x _(k))  (1)

Here, k=1−n

The amount of change in deterioration indicates the amount of change indeterioration of ES 302 within storage cell system k.

P_(k) indicates the amount of electric power (W) managed by ES 302within storage cell system k, i.e., the amount of electric power (W)that is assigned to ES 302 within storage cell system k.

x_(k) represents the state of ES 302 within storage cell system k (inthe present exemplary embodiment, temperature T₀ of ES 302 in storagecell system k, ambient temperature T_(E) of ES 302 in storage cellsystem k, and the amount of reduction of capacity D_(total,k) of ES 302in storage cell system k).

D_(k)(P_(k), x_(k)) represents the amount of the reduction of capacitywhen ES 302 in storage cell system k is used for a time interval Δtunder conditions in which ES 302 in storage cell system k is in statex_(k) and ES 302 in storage cell system k is allotted an amount ofelectric power P_(k), i.e., D_(k)(P_(k), x_(k)) represents the amount ofchange in the deterioration of ES 302 in storage cell system k.

In addition, storage unit 52 stores the minimum value P_(min,k) andmaximum value P_(max,k) of the amount of charging/discharging of ES 302for each ES 302 within storage cell systems 31-3 n.

When temperature is the overriding factor among causes of the reductionof capacity of ES 302 within storage cell system k, D_(k) follows theArrhenius law and the square root law, whereby D_(k) can beapproximately represented as in the following Formula (2):

$\begin{matrix}{{D_{k}\left( {P_{k},T_{0},T_{E},D_{{total},k}} \right)} = {\frac{a_{1,k}}{D_{{total},k}}{\int_{0}^{\Delta \; t}{{\exp \left( \frac{a_{\; {2,k}}}{T_{k}\left( {P_{k},T_{0},T_{E},t} \right)} \right)}{dt}}}}} & {{Formula}\mspace{14mu} (2)}\end{matrix}$

where a_(1,k) and a_(2,k) are constants relating to deteriorationinherent to ES 302 within storage cell system k.

The function T_(k)(P_(k),T₀, T_(E),t) in Formula (2) is a formula thatrepresents the change in temperature of ES 302 in storage cell system kand is a function that gives the temperature at time t where time 0 isthe current time, temperature T₀ is the current temperature of ES 302,and temperature T_(E) is the current ambient temperature of ES 302. Forexample, the function T_(k)(P_(k), T₀, T_(E),t) can be represented as inthe following Formula (3):

Formula (3)

T _(k)(P _(k) , T ₀ , T _(E) , t)=(T ₀ −T _(E) +a _(3,k) P)exp(ta_(4,k))−a _(3,k) P+T _(E)  (3)

where a_(3,k) and a_(4,k) are constants relating to the deteriorationinherent to ES 302 in storage cell system k.

In Formula (2), the values corresponding to x_(k) of Formula (1) are T₀,T_(E), and D_(total,k), and a_(1,k), a_(2,k), and a_(4,k) in Formula (2)and Formula (3) are constants.

FIG. 2 shows an example of the values of D_(k) when temperature T₀ is15, 20, and 25 degrees.

In addition, D_(k) is not limited to values specified in Formula (2) andFormula (3) and can be modified as appropriate.

In the present exemplary embodiment, storage unit 52 stores Formula (2)and Formula (3) as correlation information for each ES 302 in storagecell systems 31-3 n.

Determination unit 53 is one example of the determination means.

Determination unit 53 receives the detection results of temperature T₀of each ES 302, the detection results of ambient temperature T_(E) ofeach ES 302, the calculation results of the amount of reduction ofcapacity D_(total,k) of each ES 302, and electric power information thatindicates the amount of regulated power P_(t). The detection results oftemperature T₀ of each ES 302, the detection results of ambienttemperature T_(E) of each ES 302, and the calculation results of theamount of reduction of capacity D_(total,k) of each ES 302 are examplesof state information.

Determination unit 53 determines the amount of electric power P_(t) tobe allotted to each ES 302 based on the detection results of temperatureT₀ of each ES 302, the detection results of ambient temperature T_(E) ofeach ES 302, the calculation results of the amount of reduction ofcapacity D_(total,k) of each ES 302, the correlation information instorage unit 52, and electric power information that indicates theamount of regulated electric power P_(t) so as to minimize the amount ofincrease of the deterioration of each ES 302 that is caused by the useof each ES 302 in the regulation of the balance between electric powersupply and demand.

In the present exemplary embodiment, determination unit 53 determinesthe amount of electric power P_(k) that is to be allotted to each ES 302based on the detection results of temperature T₀ of each ES 302, thedetection results of ambient temperature T_(E) of each ES 302, thecalculation results of the amount of reduction of capacity D_(total,k)of each ES 302, the correlation information in storage unit 52, and theelectric power information that indicates the amount of regulated powerP_(t) such that the total value of the amount of change in deteriorationD_(k) of each ES 302 is minimized under conditions in which the state ofeach ES 302 is the state notified from each storage cell system (thedetection results of temperature T₀ of each ES 302, the detectionresults of ambient temperature T_(E) of each ES 302, and the calculationresults of the amount of reduction of capacity D_(total,k) of each ES302) and the total value of the amount of electric power allotted toeach ES 302 is the amount of regulated power P_(t).

When the state of each ES 302 has not been reported from each storagecell system, determination unit 53 estimates the state of each ES 302 bymeans of the correlation information that is maintained in storage unit52. Determination unit 53 then determines the amount of electric powerP_(k) to be allotted to each ES 302 based on the estimated state of eachES 302, the correlation information in storage unit 52, and the electricpower information that indicates the amount of regulated power P_(t),similar to a case in which the states have been reported. For example,determination unit 53 is able to estimate the current temperature ofeach ES 302 by substituting into Formula (3) detection results of thetemperatures of each ES 302 that were received in the past, detectionresults of ambient temperatures of each ES 302 that were received in thepast, calculation results of the amount of reduction of capacity thatwere received in the past, and the amount of regulated power that wastransmitted by way of control unit 54 in the past, is able to estimatethe amount of change up to the present time of the amount of reductionof capacity by substituting these values into Formula (2), and is ableto estimate the current amount of deterioration of capacity of each ES302 by adding this value to the amounts of reduction of capacity of eachES 302 that were received in the past.

Even in a case in which the state of each ES 302 has been reported fromeach storage cell system, an improvement of the accuracy of thecorrelation information may be achieved if determination unit 53estimates the state of each ES 302 and then compares these estimatedresults with the reported states to amend the correlation informationthat is kept in storage unit 52.

Examples of the state of each ES 302 notified to determination unit 53from each storage cell system include, in addition to the detectionresults of temperature T₀ of each ES 302, the detection results of theambient temperature T_(E) of each ES 302, and the calculation results ofthe amount of reduction of capacity D_(total,k) of each ES 302: theinternal impedance value of each ES 302, the thickness of each ES 302,the volume of each ES 302, the internal pressure of each ES 302, thenumber of charge/discharge cycles up to the current time of each ES 302,the cross-terminal voltage of each ES 302, and the SoC value of each ES302 that is shown in the second exemplary embodiment to be describedlater.

Control unit 54 is one example of control means.

Control unit 54 controls the operation of each ES 302 based on thedetermination results of determination unit 53. In the present exemplaryembodiment, control unit 54 transmits to each of storage cell systems31-3 n operation instructions indicating electric power P_(k) that is tobe allotted to each ES 302 that was determined by determination unit 53.

The operation is next described.

FIG. 3 is a sequence diagram for describing the operation of an electricpower control system. In FIG. 3, only storage cell system 3 c amongstorage cell systems 31-3 n is shown in the interest of simplifying theexplanation.

When EMU 4 calculates the amount of regulated power P_(t) and transmitselectric power information indicating the amount of regulated power Ptto cell management unit 5 (Step S301), determination unit 53 in cellmanagement unit 5 receives the electric power information.

Upon receiving the electric power information, determination unit 53transmits a request to report state (hereinbelow referred to as a “statereport request”) to each of storage cell systems 31-3 n by way ofcommunication unit 51 (Step S302).

In each of storage cell systems 31-3 n, upon receiving the state reportrequest by way of communication unit 301, BMU 304 transmits thedetection results of temperature detector 304 a (the temperature T₀ ofES 302), the detection results of temperature detector 304 b (theambient temperature T_(E) of ES 302), and the calculation results of theamount of reduction of capacity D_(total,k) of ES 302 as state reportsto cell management unit 5 by way of communication unit 301 (Step S303).

In cell management unit 5, upon receiving the state reports from each ofstorage cell systems 31-3 n, determination unit 53 executes an operationto determine the amount of electric power P_(k) to be allotted to eachES 302 (Step S304).

In the present exemplary embodiment, determination unit 53 in Step S304determines the amount of electric power P_(k) to be allotted to each ES302 that simultaneously satisfies the following Formula (4), Formula(5), and Formula (6).

Formula (4)

P _(t)−Σ_(k=1) ^(N) P _(k)=0  Formula (4)

Formula (5)

P _(min,k) ≦P _(k) ≦P _(max,k)  Formula (5)

Formula (6)

Σ_(k=1) ^(N) D _(k)(P _(k) , x _(k))→min  Formula (6)

For example, determination unit 53 finds a plurality of sets of electricpower amounts P₁-P_(n) of each ES 302 in storage cell systems 31-3 nthat satisfy Formula (4) and Formula (5), finds the total value of D_(k)for each set, and then determines the sets of the amounts of electricpower P₁-P_(n) for which the total values of D_(k) are a minimum as theelectric power amounts P₁-P_(n) that are to be allotted to each ES 302in storage cell systems 31-3 n.

For example, in some cases determination unit 53 gives values ofP₁-P_(n) such that dD_(k)/dP_(k), which are the values obtained bydifferentiating D_(k) by each P_(k), are identical, with the exceptionof cases in which the values of P₁-P_(n) are amounts of electric powerwhere P_(k)=P_(min,k) or P_(k)=P_(min,k).

Determination unit 53, upon determining the amounts of electric powerP₁-P_(n) that are allotted to each ES 302 in storage cell systems 31-3n, supplies these determination results to control unit 54.

Control unit 54, upon receiving the determination results ofdetermination unit 53, transmits by way of communication unit 51operation instructions indicating the amounts of electric power thatwere determined for ES 302 within the storage cell system for each ofstorage cell systems 31-3 n (Step S305).

In each of storage cell systems 31-3 n, BMU 304, upon receiving theoperation instructions by way of communication unit 301, uses inverter303 to charge ES 302 by the amount of electric power indicated in theoperation instruction when the amount of electric power indicated in theoperation instruction is a positive value (Step S306).

On the other hand, when the amount of electric power indicated in theoperation instruction is a negative value, BMU 304 uses inverter 303 todischarge the amount of electric power indicated in the operationinstruction from ES 302 (Step S306).

The effect of the present exemplary embodiment is next described.

According to the present exemplary embodiment, storage unit 52 storesfor each ES 302 correlation information that indicates the correlationof the state of ES 302, the amount of electric power allotted to ES 302,and the amount of change in the performance of ES 302 (the amount ofchange in deterioration).

Determination unit 53 receives state information that indicates thestate of each ES 302 and electric power information that indicates theamount of regulated power required for the regulation of the balancebetween electric power supply and demand. Determination unit 53, basedon the correlation information, the state information, and the electricpower information, determines the amount of electric power that is to beallotted to each ES 302 such that the total value of the amount ofchange of performance (amount of change in deterioration) of each ES 302is minimized under conditions in which the state of each ES 302 is thestate indicated by the state information and the total value of theamount of electric power allotted to each ES 302 is the amount ofregulated power.

Control unit 54 controls the operation of each ES 302 based on thedetermination results of determination unit 53.

As a result, electric power can be assigned to a plurality of ES 302such that variability in the performance of the plurality of ES 302 thatare used for regulating the balance between electric power supply anddemand is reduced.

The above-described effect is exhibited even by cell management unit 5that is made up by storage unit 52, determination unit 53, and controlunit 54.

FIG. 4 shows cell management unit 5 that is made up of storage unit 52,determination unit 53, and control unit 54.

In the present exemplary embodiment, the amount of deterioration of ES302 was used as the amount of variability in the performance of ES 302.

As a result, electric power can be assigned to a plurality of ES 302such that the deterioration of the plurality of ES 302 that are used forregulating the balance between electric power supply and demand isreduced.

In the present exemplary embodiment, moreover, ES 302 (storagebatteries) are used as the regulating devices for regulating the balancebetween electric power supply and demand in an electric power system,and the temperature of ES 302, the ambient temperature of ES 302, andthe amount of reduction of capacity from the initialization of ES 302are used as the states of the regulating devices.

Thus, when temperature in particular is taken as the overriding factoramong the causes of the reduction (deterioration) of capacity of ES 302,electric power can be assigned to a plurality of ES 302 such that thedeterioration of the plurality of ES 302 is reduced.

In FIG. 1, determination unit 53 and control unit 54 were shown asseparate apparatuses, but determination unit 53 may incorporate controlunit 54.

In FIG. 1, moreover, a regulating device control system that includescommunication unit 51, storage unit 52, determination unit 53, andcontrol unit 54 is incorporated in cell management unit 5, but all ofcommunication unit 51, storage unit 52, determination unit 53, andcontrol unit 54 need not be incorporated in the same apparatus.

In the present exemplary embodiment, determination unit 53 acquires thestate of each ES 302 after receiving electric power information thatindicates the amount of regulated power, but determination unit 53 mayalso acquire the states of each ES 302 before receiving the electricpower information.

Alternatively, determination unit 53 may repeat the operations of StepsS302, S304, and S305 shown in FIG. 3 within time intervals betweenreceiving electric power information.

Cell management unit 5 may also be realized by a computer. In this case,the computer reads and executes a program that is recorded on arecording medium such as a CD-ROM (Compact Disk Read Only Memory) thatcan be read in a computer and then functions as communication unit 51,storage unit 52, determination unit 53, and control unit 54. Therecording medium is not limited to a CD-ROM and can be modified asappropriate.

Second Exemplary Embodiment

The second exemplary embodiment of the present invention is nextdescribed.

FIG. 5 shows an electric power control system that adopts the regulatingdevice control system of the second exemplary embodiment of the presentinvention. In FIG. 5, constructions that are identical to those shown inFIG. 1 are given the same reference numbers. The following explanationfocuses on points of the electric power control system shown in FIG. 5that differ from the electric power control system shown in FIG. 1.

Although the regulating device control system of the first exemplaryembodiment used correlation information suited to a case in whichtemperature was the overriding factor among causes of the reduction(deterioration) of capacity of ES 302, the regulating device controlsystem of the second exemplary embodiment uses correlation informationsuited for a case in which the SoC (State of Charge) of ES 302 is theoverriding factor as a cause of the reduction (deterioration) of thecapacity of ES 302.

In FIG. 5, each of storage cell systems 31-3 n includes BMU 304A inplace of BMU 304 and leaves out temperature detectors 304 a and 304 b;and cell management unit 5 includes storage unit 52A in place of storageunit 52 and includes determination unit 53A in place of determinationunit 53.

BMU 304A, similar to BMU 304, controls inverter 303 in accordance withoperation instructions from cell management unit 5 to control thecharging and discharging of ES 302.

In addition, BMU 304A calculates and manages SoC₀, which is the currentSoC value of ES 302, the current capacity C_(k) of ES 302, and theamount of reduction of capacity D_(total,k) from the initialization ofES 302. BMU 304A transmits SoC₀ of ES 302, the current capacity C_(k) ofES 302, and the amount of reduction of capacity D_(total,k) frominitialization of ES 302 to cell management unit 5 by way ofcommunication unit 301.

The techniques of computing SoC₀ of ES 302, the current capacity C_(k)of ES 302, and the amount of reduction of capacity D_(total,k) from theinitialization of ES 302 are known technology and detailed explanationis therefore here omitted.

SoC₀ of ES 302, the current capacity C_(k) of ES 302, and the amount ofreduction of capacity D_(total,k) from the initialization of ES 302 areexamples of the state of ES 302.

Storage unit 52A is one example of the memory means.

Storage unit 52A stores the following Formula (7) and Formula (8) as theabove-described Formula (1).

$\begin{matrix}{{Formula}\mspace{14mu} (7)} & \; \\{{D_{k}\left( {P_{k},{SoC}_{0},C_{k},D_{{total},k}} \right)} = {\frac{b_{1,k}}{D_{{total},k}}{\int_{0}^{\Delta \; t}{{\exp \left( {b_{2,k}{V\left( {{SoC}_{0} + \frac{P_{k} \cdot t}{C_{k}}} \right)}} \right)}{dt}}}}} & {{Formula}\mspace{14mu} (7)}\end{matrix}$

Here, b_(1,k) and b_(2,k) are constants relating to deteriorationinherent to ES 302 in storage cell system k.

Formula 8

V(SoC)=b _(3,k)SoC³ +b _(4,k)SoC² +b _(5,k)SoC+b _(6,k)

Here, b_(3,k), b_(4,k), and b_(6,k) are constants relating todeterioration inherent to ES 302 in storage cell system k.

Function V(SoC) in Formula (7) is a formula that expresses thecross-terminal voltage of ES 302 in storage cell system k and that takesthe value SoC as an argument. In addition, because we wish to know thecross-terminal voltage at time t in Formula (7), SoC value at timet=(SoC₀+P_(k)t/C_(k)) is taken as an argument. Formula (8) is a valueobtained by, for example, approximating the function V(SoC) in Formula(7) by a polynomial.

In Formula (7), the values that correspond to x_(k) of Formula (1) areSoC₀, C_(k), and D_(total,k): and b_(1,k), b_(2,k), b_(3,k), andb_(4,k), which are values representing the deterioration inherent to ES302, are constants.

FIG. 6 shows an example of the values of D_(k) when SoC₀ is 0.5, 0.6,and 0.7.

In addition, storage unit 52A stores for each ES 302 in storage cellsystems 31-3 n the minimum value P_(min,k) and maximum value P_(max,k)of the amount of charging/discharging of ES 302.

Determination unit 53A is one example of the determination means.

Determination unit 53A receives SoC₀ of each ES 302, the currentcapacity C_(k) of each ES 302, the amount of reduction of capacityD_(total,k) from initialization of each ES 302, and electric powerinformation that indicates the amount of regulated power P_(t). The SoC₀of each ES 302, the current capacity C_(k) of each ES 302, and theamount of reduction of capacity D_(total,k) from initialization of eachES 302 are examples of state information.

Based on Formula (7) and Formula (8) in storage unit 52A, SoC₀ of eachES 302, the current capacity C_(k) of each ES 302, the amount ofreduction of capacity D_(total,k) from initialization of each ES 302,and electric power information that indicates the amount of regulatedpower P_(t), determination unit 53A determines the amount of electricpower P_(k) to be allotted to each ES 302 that simultaneously satisfiesthe above-described Formula (4), Formula (5), and Formula (6).

Upon determining the amounts of electric power P₁-P_(n) to be allottedto each ES 302 in storage cell systems 31-3 n, determination unit 53Asupplies the determination results to control unit 54.

Control unit 54, upon receiving the determination results ofdetermination unit 53, transmits operation instructions indicating theamount of electric power that was determined to ES 302 in the storagecell system by way of communication unit 51.

According to the present exemplary embodiment, ES 302 (storage cells)are used as regulating devices for regulating the balance betweenelectric power supply and demand of an electric power system, and theSoC of ES 302, the current capacity of ES 302, and the amount ofreduction of capacity from initialization of ES 302 are used as thestates of the regulating devices.

As a result, when the SoC value has a particularly large effect incausing the reduction (deterioration) of capacity of ES 302, electricpower can be assigned to a plurality of ES 302 such that thedeterioration of the plurality of ES 302 is reduced.

In FIG. 5, determination unit 53A and control unit 54 are shown asseparate components, but determination unit 53A may incorporate controlunit 54.

In addition, although a regulating device control system that includescommunication unit 51, storage unit 52A, determination unit 53A, andcontrol unit 54 is incorporated in cell management unit 5 in FIG. 5, allof communication unit 51, storage unit 52A, determination unit 53A, andcontrol unit 54 need not be incorporated in the same apparatus.

Cell management unit 5 shown in FIG. 5 may be realized by a computer. Inthis case, the computer reads and executes a program that is recorded ona recording medium that can be read in the computer to function ascommunication unit 51, storage unit 52A, determination unit 53A, andcontrol unit 54.

In each of the above-described exemplary embodiments, each ES 302 may bestorage cells having mutually differing properties, or may be storagecells having identical properties.

In each of the above-described exemplary embodiments, EMU 4 may take thevalue of the amount of regulated power P_(t) as a negative value whendemand for electric power is necessary for regulating the balancebetween electric power supply and demand, and may take the value ofamount of regulated power P_(t) as a positive value when supply ofelectric power is necessary for regulating the balance between electricpower supply and demand. In this case, when the amount of electric powerindicated by an operation instruction is a negative value, BMU 304 usesinverter 303 to charge ES 302 with the amount of electric powerindicated by the operation instruction. On the other hand, when theamount of electric power indicated by the operation instruction is apositive value, BMU 304 uses inverter 303 to discharge the amount ofelectric power indicated by the operation instruction from ES 302.

In each of the above-described exemplary embodiments, the amount ofchange in the performance of ES 302 is not limited to the amount ofchange in deterioration of ES 302 and can be modified as appropriate.

In each of the above-described exemplary embodiments, the configurationsshown in the drawings are merely examples and the present invention isnot limited to these configurations.

Although the invention of the present application has been describedwith reference to each of the exemplary embodiments, the invention ofthe present application is not limited to the above-described exemplaryembodiments. The configuration and details of the invention of thepresent application are open to various modifications within the scopeof the invention of the present application that will be clear to one ofordinary skill in the art. This application claims the benefits ofpriority based on Japanese Patent Application No. 2012-041609 for whichapplication was submitted on Feb. 28, 2012 and incorporates by citationall of the disclosures of that application.

EXPLANATION OF THE REFERENCE NUMBERS

1 electric power system

2 power line

31-3 n storage cell system

301 communication unit

302 ES

303 inverter

304, 304A BMU

304 a, 304 b temperature detector

4 EMU

5 cell management unit

51 communication unit

52, 52A storage unit

53, 53A determination unit

54 control unit

1-6. (canceled)
 7. A regulating device management apparatus that controls the operation of a plurality of regulating devices for regulating a balance between electric power supply and demand in an electric power system, comprising: a communication unit that receives temperature information of each of said regulating devices; and a computer processor that determines electric power information to be allotted to each of said regulating devices such that the electric power information to be allotted to each of said regulating devices become larger in relation to decreasing temperature of each of said regulating devices based on correlation information, that represents correlation of the temperature information of said regulating device, an amount of electric power to be allotted to the regulating device and an amount of variability in performance of the regulating device, under conditions in which the total value of the amount of electric power information to each of said regulating devices is regulated power information that is necessary for the regulation of said balance between electric power supply and demand, and transmits the determined electric power information to be allotted to each of said regulating devices to each of said regulating devices.
 8. The regulating device management apparatus according to claim 7, wherein the temperature information includes at least a body temperature of said regulating device or an ambient temperature of said storage cells.
 9. The regulating device management apparatus according to claim 7, wherein the electric power information is electric power or an amount of electric power.
 10. The regulating device management apparatus according to claim 8, wherein said computer processor determines the amount of electric power to be allotted to each of said regulating devices such that a total value of the amount of variability in the performance of each of said regulating devices is minimized.
 11. The regulating device management apparatus according to claim 7, wherein the amount of variability in performance of said regulating devices is an amount of variability in deterioration of said regulating devices.
 12. The regulating device management apparatus according to claim 7, wherein said regulating devices are storage cells; the temperature information include a temperature of said storage cells and an ambient temperature of said storage cells; and said computer processor further uses an amount of reduction of capacity from the initialization of said storage cells in order to determine electric power information to be allotted to each of said regulating devices.
 13. The regulating device management apparatus according to claim 7, wherein said regulating devices are storage cells; said computer processor further uses State of Charge (SOC) of said storage cells, a capacity of said storage cells, and an amount of reduction of capacity from the initialization of said storage ceils in order to determine electric power information to be allotted to each of said regulating devices. 